Fluid circulating system



July 25, 1939.- s. F. SHAWH E; AL 2,167,466

FLUID CIRCULA TING SY$TEI Filed Jan. '22, 1936 m g u 6 w 89 11 3 m H 6 2 n a a a a 53% fif Mi Q =6 Z M H 7 FF:

IN V EN TORS Patented-July 25, 1932:

UNITED STATES PATENT OFFICE FLUID CIRCULATING SYSTEM Application January 22, 1936, Serial No. 60,198 a 1 Claim.

This invention relates to air conditioning apparatus.

It is common practise in the air conditioning art to pass air through a casing in which it is subjected to the action of sprayed liquid and, in some cases, passed in contactwith heat exchange coils. Apparatus of this type may be used for cooling and dehumidiiying air, orv for heating and humidifying air, or as an evaporative condenser, in accordance with the teachings of co-pending Patent No. 2,059,839, issued November 3, 1936. I

The general object of the invention is to provide an improved strainer and pump arrangement for heat exchange apparatus of this type.

It is an object of the invention to provide an improved strainer for removing foreign matter from the water drawn from the sump of a heat exchange device.

It is another object of the invention to provide an improved pump for withdrawing water from the sump of a heat exchange device through the above mentioned strainer, and for supplying the water to a series of spray headers adapted to discharge the water within the device.

It is another object of the invention 'to provide a sump, strainer, and pump arrangement in which water may be withdrawn from the sump by the pump through the strainer, and in which other water from the sump may be simultaneously discharged through the strainer and through the pump.

A feature of the invention resides in the provision'of a pump having two main sections. In the lower section, water is drawn into the impeller and discharged thereby through a suit"- able opening in the pump housing. The upper section of the pump is provided with two openings. One of these openings provides communi cation between the upper section of the pump housing and the tank containing the filter. The

second opening is adapted to discharge water from the upper section of the. pump housing through a suitable overflow pipe, or the like.-

When water is supplied to the sump of the heat exchange device at a rate greater than the rate at which water is evaporated therein, water from I the sump maybe passed through the first and second openings in the upper section of the pump housing.

Another feature of the invention resides in the combination of an electric motor. a pump, the .motor and pump having a. common shaft, and a disk on the shaft to prevent passage of water from the pump to the motor. This construction permits the elimination of stufling boxes and the like, and the friction resulting therefrom.

Another feature of the invention resides in the provision of a drain opening formed in the bottom of the pump housing.

Another feature of the invention resides in mounting a strainer box outside the sump of a heat exchange device, water from the sump being drawn through and filtered in the strainer box.

Still another feature of the invention resides in the provision of a strainer box, in which the strainer is attached to the cover of the box, whereby the strainer may be readily removed from the box, by removal of'the coverr'for inspection, cleaning, .repair or replacement.

- Another feature of the invention resides in the provision of a strainerbox having three openings. Through the first ofthese openings, water passes into the strainer box. Through the second of these openings, water is drawn from the strainer box by the pump. Through a third of these openings water may be passed to the strainer box from the upper section of the pump housing, ,or passed from the strainer box to the uppersection of the pump housing.

Another feature of the invention resides in straining all water supplied from the sump to the lower secti'onof the pump, and all water passing from the same sump (of the heat exchange device) to the upper section of the pump housing.

Other objects, features and advantages of the invention will be more apparent from the following description to be read in connection with the accompanying drawing in which Fig. 1 is adiagrammatic view, in elevation, of a heat exchange apparatus embodying the invention.

Fig. 2 is an elevational view, partly in section, illustrating applicants pump, strainer and sump 40 arrangement; and v Fig. 3 is an elevational view, in section, illustrating a modified form of applicants"strainer.

Referring now to. the drawing, 5 designates generally the casing of a heat exchange device in which are positioned heatexchange coils 6. Air is blown over the coils in any suitable man-a ner. Water is supplied to the sump I of easing 5 through supply pipe I 'underthe control of valve 8. Water from the sump I is drawnby a' pump, generally designated ll, through strainer box u. and is discharged through pi I! spray headers l3, which discharge over the tubes 6. The'unevaporated portion ot-* water from the headers I 3 is returned to sump 1 for recirculation through the system.

Referring more particularly to Fig. 2, pump I0 comprises two main sections, separated from each other by plate l4. In the lower section is housed impeller I 5 which draws in water through intake l6, and discharges it into scroll ll, whence it passes to pipe [2. Impeller I5 is mounted on shaft I8 by collar l9, which extends upwardly from the lower section into the upper section of the pump housing, through an opening in plate l4. Collar I9 is secured to shaft l8 by a screw 20, or in any other suitable manner. Shaft I8 constitutes an extension of the armature shaft of motor 21, which is mounted above and drives pump It. In operation, water will tend to flow upwardly between collar l9 and plate I4; also between shaft [8 and collar l9. To prevent such water from entering and affecting the motor, applicants provide .disk 22 on shaft I8. Water which tends to enter the motor casing, encounters the whirling disk 22, and is flung therefrom,

by centrifugal force, against the sides of the| Dump housing.

The upper section of the, pump housing is provided with two openings. The first of these, 23, provides communication between the upper section of the pump housing, and the filter box II. The second opening, 24, receives drain pipe,

or the like, 25. Preferably the level of the opening 24 is higher than that of opening 23. Preferably also, a baflie 38 is positioned in front of opening 24-, to prevent the throwing of water from disk 22 directly therethrough.

Filter box H is provided with three openings. A first of these, 26, matches the opening l6 of the pump housing. A second opening, 21, matches the opening 23 of the pump housing. A third opening 28, provides communication between the filter box H, and the sump I. Preferably, opening 28 is located slightly above the bottom of sump I, so that heavy sediment will acccumulate in the bottom of the sump and will not clog the strainer. Filter box II is provided with a removable cover'29. r Attached to cover 29 and adapted to be removed therewith -is a screen 30. Inwardly extending flanges 3| and 32 of the filter box l I, are adapted to co-act with supporting frame members 33 and 34, attached to the cover 29 and to'screen 30. Screen takes the form of a basket into which is discharged all water passing from sump I. All water drawn into the pump through opening 28 necessarily passes through screen 30, so that foreign matter is prevented from being drawn into the pump structure by impeller l5.

In a prefered form of the invention, valve 9 is a solenoid valve, operative to admit water through pipe 8 to sump 1 when motor 2| is operative. Preferably, also, valve 9 is adjustable, so that water may be supplied to the sump at any desired rate while pump I0 is drawing water from the sump. In practice, valve 9 is' so adjusted that the normal water level in sump -1 and filter box II is above the top of the intake opening l6 of the pump housing. In this way cavitation of the pump is avoided.

When the air supplied to heat exchange device 5 is of such character as to render corrosive the water with which. it contacts, (by the formation of acids, or the like.) it is undesirable to recirculate the same water over long periods. On the contrary, it is desirable to change the water in the system, in order to keep its'acid concentration below a predetermined value. Un-

der such circumstances, valve 9 is adjusted to supply water to the sump at a greater rate than that at which liquid is evaporated. The excess water in the system passes through the opening 21 of the filter box H and openings 23 and 24 of the pump housing, and is drained through pipe 25. To prevent the entrance into the pump housing of foreign matter from. the sump, applicant provides screen 35, attached to cover 29. Screen 35 may constitute an extension of screen 30, or may be of a different material or fineness.

A drain opening 36 is formed in the bottom of the pump housing. The pump may be drained by removal of plug 31, positioned within opening 36.

In the modification shown in Fig. 3, screen 30a, corresponding to screen 30, takes the form of a continuous wall extending completely across the filter box, rather than the basket shape illustrated in Fig. 2. To increase the effective filtering surface, applicant corrugates the screen.

If desired, of course, opening 28 may be located at the bottom of sump l.

Thescreen frame members 33 and 34, and their associated ledges 3| and 32, serve to seal the intake of the pump. Were it not for this seal, the pump might draw in air in the event strainer 30 became clogged, but applicants structure obviates all possibility of cavitation in this manner. As a further precaution against cavitation, applicants prefer to maintain the normal liquid level above plate I4. Thus, although under certain conditions (as when strainer 30 becomes clogged) the pressure within the pump structure may fall, applicants water seal prevents the drawing of air into the pump through the space between plate l4 and. collar 19, and through the space between collar l9 and shaft l8. It will be seen, therefore, that applicants pump is completely and effectively sealed.

It is to be observed that the motor and im peller may be removed for inspection, replacement or repair, without draining the pump or interference with the piping.

Since many modifications may be made in the invention without departing from the scope thereof, -it is to be understood that the above description and the accompanying drawing are intended as illustrative only, applicants limiting themselves only as indicated in the appended claim.

We claim:

In a gas and liquid contact apparatus of the character described, a casing through which there is adapted to be circulatedair which may contain impurities such as dirt particles and acid fumes, means for discharging liquid in contact with said air within said casing, a sump formed at the bottom of said casing for collecting liquid which has contacted with said air, a pump adapted. to withdrawv liquid from said swim and to supply said withdrawn liquid to said liquid discharge means, said pump being positioned ex- 2,167,4 66 said driving means for controlling said valve and adapted to cause opening of said valve when said driving means is operative, a first opening formed in the upper section of said pump, a second opening formed in the upper section of said pump and communicating with said sump through the interior of the upper pump section and saidfirst opening, means providing communication between said first opening and said sump, the bottom of said first opening being lower than the liquid level in said sump whereby to form ,a liquid seal upon the lower section of said pump to avoid cavitation therein, the hottomfor said second opening being formed at a. higher level than the bottom of said first opening and being adapted to discharge fluid -from the system whenever the liquid level in the upper pump section rises above the lowest point" of said second opening, whereby liquid may be supplied to said sump at a greater'rate than that at which the circulated liquid is evaporated or otherwise carried off by the circulated air, and,

whereby there may be eifected a constant and gradual change of the liquid circulated through the apparatus and a constant and gradual elimination from the system of impurities and the like transferred from said air to said circulated liquid. SAMUEL F. SHAWHAN. CARLYLE M. ASHLEY. 

